Combined air conditioning and heating unit



June 29, 1943. w. w. HALLINAN COMBINED AIR CONDITIONING AND HEATING UNITFiled July 22, 1940 5 Sheets-Sheet 1 June 2%, 1943., w w H L 2,323,034-

COMBINED AIR CONDITIONING AND HEATING UNIT Filed July 22, 1940 5Sheets-Sheet 2 x, Q u w w a s w L55 Q6 Q7 43 32 gi y June 29, 1943. w.w. HALLINAN COMBINED AIR CONDITIONING AND HEATING UNIT Filed July 22,1949 5 SheetsSheet 3 km ZZZ Imam;

June 29, 1943. w. w. HALLINAN 2,323,034

COMBINED AIR CONDITIONING AND HEATING UNIT Filed July 22, 1940 5Sheets-Sheet 4 JIM/420502".

ii z Mzzzlm 22 9 21 2 0 @w f 'w f June 29, 1943. w. w. HALLINAN COMBINEDAIR CONDITIONING AND HEATING UNIT Filed July 22, 1940 5 Sheets-Sheet 5 vNRN QNY wn w 2 Patented'June 29, 1943 PATENT OFFICE COMBINED AIRCONDITIONING AND HEATING UNIT v William W. Hallinan, Mendota, Ill.Application July 22, 1940, Serial No. 346,763

16 Claims.

The present invention relates to combined air conditioning units, and isparticularly concerned with heating units of the coal stoker type,including arrangements for effecting a filtering and circulation of theheated air, and for maintaining the air of one or more rooms at apredetermined temperature with a maximum eflleiency.

.One of the objects of the present invention is .the provision of animproved heating and airconditioning unit of the stoker type in whichthe blowers for circulating air and for providing the air for combustionare all driven from the same motor and in which the stoker and furnaceare all embodied in one housing so that they are adapted to be installedas a unit.

Another object of the invention is the provision of an improved heatingand air conditioning unit of the stoker type in which the hopper for thestoker is located inside the hous ing and subjected to cool-ing by thecirculation of coldair about the hopper so that there is no hazard dueto the possibility of ignition of fuel in the hopper and no possibilityof the escape of smoke from the hopper into the furnace room or aircirculation channels.

Another object of the invention is the provision of an improved airconditioning and heating unit of the stoker type, which is capable ofeconomical manufacture, and which is sturdy and adapted to be easilycleaned, and in which all of the moving mechanism is readily availablefor inspection or repair.

Another object is the provision of an' improved stoker controllingsystem which is adapted to eliminate the-use of deep fuel beds and toregulate the coal feed and the air according to the steam pressure orbonnet temperature.

Another object of the invention is the provision of an automatic stokerfired air conditioning unit of modern design so constructed as toinclude all of the elements of winter air conditioning in one unit andso as to conserve the basement floor space.

Another object of the invention is the production of a complete winterair conditioning unit which is coal fired and which utilizes but oneelectric motor to furnish air for the combustion of the coal and air forthe circulation of air through the conditioning unit and space to beheated by it.

Another object of the invention is the provision of an improvedautomatic coal fired air conditioning unit which has a heatingefiiciency higher than that ever before attained by the devices of theprior art.

Another object of the invention is the provision of an improved airconditioning and heating unit and controlling system which is adapted toeliminate the room temperature overrun above the thermostat setting thatis commonly present in the stoker fired units of the prior art, thusconserving fuel and raising the overall efficiency of the heating unitto a maximum. Another object of the invention is the provision of animproved heating system which is adapted to operate at a high rate offuel and air feed when the bonnet temperature or steam pressure is belowa predetermined value and which is also adapted, as soon as the steampressure or bonnet temperature reaches such value, to change the fuelfeed and air supply in such manner that air will continue to be suppliedto burn the excess fuel that has :been forced into the fire pot on highfeed, thus maintaining efficient combustion without excessive coal feeduntil the fuel previously supplied has been burned up and the fire bedis reduced to a minimum depth, unless the steam pressure or bonnettemperature drops below the predetermined minimum again, in which casethe stoker is fired at high coal and air feed.

Another object of the invention is the provision of an improved airconditioning and heating unit and controlling system for it, by means ofwhich the fuel feed may be cut oil. before the room thermostat issatisfied and the furnace operated at reduced air supply, in order toconsume all of the fuel previously forced into the burner, thus reducingthe fuel bed depth to a minimum at the time or just about the time whenthe thermostat will be satisfied for the purpose of eliminating theregular room temperature over-run above the thermostat setting.

The solid fuel burners of the prior art with which I am familiar operatewith either a full fuel feed or a full air feed, or a combination ofboth, until the room thermostat is satisfied, thus causing an over-runof the thermostat setting and a stopping of the burner by the thermostatwhen there is a large fuel bed in the furnace.

This large fuel bed produces smoke and wastes the fuel at this timebecause the combustion air is also shut off in the devices of the priorart, when the fuel feed is stopped.

Another'object of the invention is to provide an improved airconditioning and heating unit it in which the same motor operates theair circulating blowers for the space. to be heated, and the blower forthe air of combustion, and in which the supply of air for combustion isnot completely shut off, but is merely redhced'so that when the motor isoperating the fuel bed in the furnace is still provided with a reducedsupply of air to reduce smoking and produce a more perfect combustion.

Another object of the invention is to produce a complete winter airconditioning unit in which the entire motor power assembly, consistingof the air conditioning blowers, burner blower, motor, and fuel feedgear casing, is easily removable and adapted to be replaced as one unit.

Another object of the invention is the provision of an air conditioningand heating unit for winter operation in which a solid fuel burner, afuel storage hopper, a furnace, an air conditioning blower, the airfilters, controls, wiring, and humidifier are all included in one unit,fully assembled and tested in such manner that the unit may be shippedfrom the factory in condition to be installed in the furnace room. andmerely connected with the chimney and electric light power supply forimmediate operation.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews.

Referring to the five sheets of drawings,

Fig. 1 is a view in perspective of the air conditioning and heating unitembodying the invention, with certain covers removed, to show thedetails of construction;

Fig. 21s a vertical sectional view, taken on the plane of the line 22 ofFig. 1. showing further details of construction of the housing andmechanism;

' Fig. 3 is a front elevational view, partially broken away, and with acover removed, to show the details of the operating mechanism and courseof circulation of the air;

Fig. 4 is a rear elevational view of the unit:

Fig. 5 is a front elevatlonal view of theunit;

Fig. 6 is a fragmentary sectional view, showing the details ofconstruction of the front wall;

Fig. 7 is a fragmentary sectional view, taken on a plane passing throughthe axis of the blowers, and showing the motor and other operatingmechanism in elevation in a modification where the blowers are locatedon the high speed'shaft of the gear box;

Fig. 8 is a similar view of another modification where the blowers arearranged on the motor shaft;

Fig. 9 is a wiring diagram showing the circuits and apparatus forcontrol of the heating system embodied in the present unit.

Fig. 10 is a. top plan view of the furnace housing, showing the airchambers surrounding the parts of the furnace.

Referring to Figs. 1 and 2, the present air conditioning and heatingunit is preferably enclosed in a sheet metal housing which issubstantially rectangular in plan and side and end elevation,

This housing preferably includes a bottom plate 29 of sheet metal whichis adapted to support all of the rest of the unit. The. bottom plate 29is preferably substantially rectangular in shape, and is provided aboutits borders with an upwardly extending flange 21 at its front Thehorizontally extending flange 22 has an upwardly extending attachmentflange 23 extending across the rear end and the two sides of thehousing, while the front end of the housing may be provided with abox-like frame member 24, forming a transverse frame member and sill foran opening leading to the operating mechanism.

The outer housing of the unit preferably includes the side panel members25, 2G and the end panel members 21, 28 (Figs. 3-5). The side panelmembers 25, 26 may be identical in shape, and they comprise sheet metalmembers provided with the straight lower border 21, and at the loweredge the side panels 25, 26 may be secured in overlapping relation tothe upwardly extending flange 23 preferably by means of screws or aPittsburg seam or clamp.

Each side panel is preferably provided at each of its vertical ends witha pair of flanges 29, 30, one at the front, and one at the rear, thesevertical flanges being at substantially right angles to the main body ofeach panel 25, 26, and the bend between the flanges being partiallycylindrical, or what may be described as an easy bend, giving theexterior of .he housing rounded corners.

The base flanges 22 are correspondingly curved, and the attachingflanges 23 correspondingly curved to fit the side panels 25, 26 at thebottom with their vertical flanges 29 and 30.

The top of the housing is preferably provided with an upper frame member3|, comprising a substantially rectangular frame of suflicient size tofit inside the side panels 25, 26 at the top. This frame has four sides,and may be made of one integral piece, or a number of pieces boltedtogether, and each side of the frame comprises a vertically extendingflange 32 adapted to fit inside the side panels 25, 26 and offset 33,and a partially cylindrical curved portion 34, which terminates with itsedge 35 extending in a substantially horizontal plane. The rear part ofthe rectangular frame 3| may be of similar construction, having itslower flange 32- engaged inside the rear end panel 21.

The rear end panel 21 may also overlap the vertically extending flanges30 of the two side panels, to which they maybe secured by welding,riveting or other convenient fastening means, welding over the fulllength being preferred.

The rear end panel 21 is preferably provided with a pair of clean-outopenings which are closed with the covers 36 31, and with anotheropening for access to the fire pot, which is closed by the cover member35. At its front end the top frame 3| has a depending flange without theoffset 33, the inside of the flange being engaged by the front panel 28.

This front panel comprises a rectangular piece of sheet metal which hasits lower edge provided with a horizontally extending flange 38 and adownwardly extending flange 39, which engage the top and inside of thebox-like sill 24.

The curved flanges 29 of the side panels are preferably provided withofisets and flanges 49 extending laterally under the end panel 28, whenit is in the position of Fig. 5. The end panel 28 is held in place onone side by the flanges 49 behind it, and on the other side by theflange 39 extending down below the sill 24, and the depending flange 32of the upper frame 3!, which is outside the end panel 28. The and panel28 may be removed by lifting it until the flange 39 clears the sill 24so that the lower end may be moved outward and downward to cause theupper edge of the end'panel II to clear the depending flange 32. w

This panel also is preferably provided with an opening which may beclosed by means of a hinged closure 4|.- This. opening is utilized foraccess to the hopper. The actual opening 42 to the hopper is preferablytrapezoidal in form, for a reason further to be described. I

At its upper end the main housing is closed by the upper frame 3|, whichhas a horizontal body portion 43, effecting a substantial closure,except for the openings 44, 45, and 45. The opening 45 is utilized. forpassage of the'smoke pipe 41, which extends to the chimney.

Openings 44 and 45 are each preferably provided with angular frameswhich are rectangular in plan and which serve for connecting the coldair ducts and hot air ducts. Each of these frames is preferably providedwith a vertical flange 48 and a horizontal flange 49. In each case thehorizontal flange is secured to the lower side of the body 44 of the topframe or panel, and the vertical. flange 48 passed through the aperture44 or 45.

All of the exterior panels or side portions of the housing, includingthe top and bottom, may be heat insulated with one or more inner layersof heat reflecting paper, corrugated asbestos cardboard, and asbestosblankets, or any one or more forms of such insulation.

The rectangular air ducts leading from the rooms may be attached to theflanges 48 and may have their lower edges resting on the tor; panel 49of the housing. The opening 44,...i. utilized for a cold air duct, andthe opening-"45v for the hot air duct.

The fire box housing, indicated by the numeral 50, preferably rests upona plurality of legs one located at each corner of the base 52. Theselegs may consist of insulating bricks or firebrick secured in place bythrough bolts or other convenient fastening means. The flre box 50 has asubstantially rectangular base 52 and side panels 59, which arerectangular in shape. 7

These side panels are joined at the rear end to a vertical end panel54,and at the other end to a front panel 54, which may be considered asbeing composed of a rectangular part and an integral trapezoidalportion.

The trapezoidal portion of this panel is used to cause the furnacehousing 50 to taper toward the top. A pair of sloping roof panels 55 areused, one on each side for covering the tapered portion of the furnacehousing 59, and another sloping panel 56 is used on the rear side andprovided with an aperture 51 leading to a rectangular box-like conduit59, which is closed by the door 35.

At its upper end (Fig. 10) the furnace is formed with a box-like portion59, which may be closed by a rectangular top plate that is provided witha U-shaped slot 59', defining an air circulation conduit inside theouter portion ofthe box 59 and surrounding the inner portion 50 of thefurnace top. This box-like portion of the furnace has a lower side plate54 of the same shape as the top plate shown in Fig. l0,-except thatthere is an aperture 54 for receiving the upwardly extending part of themain furnace housing 59. This part has. an upwardly extending framemember 55 on each side which prevents direct communication between thechamber 55 and the chamber 51. through the aperture 54, which isconnected to the chimney 4'I.

It will be noted that there are air channels extending from the airconditioning blowers through and between the furnace and upper radiatorbox and surrounding the chimney.

The box-like portion 60 is wider than the upper extension 59 of thefurnace housing, and the side plates 59 of the upper extension 59 ofmain furnace housing 60 serve as bailles. The upper extension 59 of themain furnace housing 50 has an aperture at 10 on its rear side above therear plate 54, so that the gases may pass upward in the housing 50 intothe extension 59 through the aperture 10, where they are split in twodirections, passing outside of the side plates 59 and inside of the sideplates H to the chamber 51, which is in communication with the chimney41. M 1

The clean-out openings previously described as being closed by the doors35 and 31 are in connection with the passages 12 on both sides of themain furnace housing extension 59 inside the plates 'H. with the furnacehousing by rectangular conduits 13 terminating in the doors 35, 31..

In addition to being supported on the legs 5|, which are preferablysecured to the, bottom plate 20 of the heating unit, the furnace housingis tied to the rear end wall by the clean-out door conduits 59 and Handto the top of the unit housing by the chimney ,4'I.

It will thus'be observed that the furnace housing is spaced from theunit housing on all sides so that the heated walls of the furnacehousing may come in direct contactwith air inside'the heat unit housingfor radiation and conduction of heat to the air.

The unit housing is preferably provided with a depending baflle 14extending from its top' panel 43. between the cold air opening 44 andthe hotair opening 45. This panel 14 fits the inner walls of the sidepanels 25 and 25, and is firmly secured to these panels, and itseparates the air conditioning unit housing into two chambers I5 forcold air and 15 for hot air.

In the chamber 15 the cold air is passing downwardly around the lowerend 11 of baffle 14, and in chamber 16 the air is heated and passesupwardly.

V Baflie I4 is provided with a diagonally extending offset 19 locatedbetween its upper and lower edges for the purpose of increasing the sizeof the lower part of the cold air chamber 15 by locating the lowermostportion 19 of the baflle 14 forwardly of the uppermost portion.

'The cold air chamber I5 is also adapted to house a hopper 80 which hasits filling opening at 42 (Fig. l). The upper part of the hopper 80 isclosed by a sheet metal member which may have an upwardly and diagonallyextending portion 82 and a pair of integral roof portions 83, 94 joinedtogether along a ridge 85, and another diagonally extending'portion 95.

This metal plate, consisting of the parts 8285, is symmetrical whenviewed from the front or rear, and constitutes abafile 9ll'fo'rseparating the air coming in at the cold air opening 44 into two streamsto pass outward through the air filters 81, 88, which are veijicallydisposed on These apertures are connectedclosed by the door 4| hcsivecompound and adapted to strain out of the air all types of solid foreignmaterials.

I The cold air chamber is provided with suitable vertically extendingguide members 8| for slidably receiving the frames of the filters 81,

88'to hold them in vertical position and in spaced relation to the sidepanels 25, 28 of the air conditioning junit.-'.

The filters may be slid in from the front of the air conditioning unitby removing the front panel 28, and may easily be renewed at'any time.

At their rearends the filters 81, 88 and the baf-- fie 88 engage therear wall 82 of the hopper, which may have a diagonally extendingportion 88 and a lower vertically extending portion 84. The spacebetween the bailie'14 and the wall 82 permits a smallamount of cold airto pass by the filters 81, 88 without being filtered; but it alsoservesto cool the hopper on all sides.

. In other embodiments of the invention the space between the walls 82and 14 may be blocked oil so as to cause all of the air to passthroughthe filters and still maintain a dead air space surrounding the hopper.

The hopper 88 may have its front wall 85 formed of a piece of sheetmetal of substantially rectangular form, which extends upward and isjoinedat the top to the baflle member 88. This front wall has the hopperaperture 42, which is The rectangular front wall 95 of the hopper isbent backwardly at 88 and has a diagonal downwardly extending portion 81adapted to guide the fuel in the hopper over into the rectangular feedbox 88.

The sides of the'hopper may be formed by a pair of panels secured to theplate portions 85,

88, 81, 88, 84 and of ashape shown in Fig. 2 and having a downwardlyextending rectangular portion 88 forming the sides of the feed box 88.

I cut awayv to form an openingwhere it engages the bottom'of, the hopperso that the fuel may flow freely from .the hopper into the conveyor tubewhere it isengaged by a screw conveyor.

The end walls I88 and IN, being trapezoidal and tapering toward theirlower edges, causes theside panels 88 of the feed box to slope towardeach other todirect the fuel into the conveyor tube I88.

The feed box'88 preferably .has an opening in its front wallI8I,communlcatlng with a box-like extension I85 fitted on a continuationof the: same opening in the conveyor tube I88, and having a closureplate I88 secured by a bolt and thumb screw I81. This closure plate I88may be removed for inspection of the conveyor screw and to removeobstructions.

The conveyor tube I88 communicates at its rear end with the fire potI88, which may be of any desired construction, and which is providedwith suitable grate formations for supporting the fuel that is forcedupwardly at its center and spread out on the top of the fire pot.

The fire pot I88 also communicates below its grate and surrounding itsfuel feeding aperture with the air supply tube l 88, which is bentbackwardly and communicates with the blower housing II8 located beneaththe diagonal wall 81 of the hopper. The air tube I88 is preferablyprovided with'a butterfly damper II I located intermediate its length inan enlarged portion H2.

The space below the hopper wall 81, air conditioning unit end panel 28,and hopper wall I88, which is also bound by vertically extending airbafiies H8, H4, is indicated by the numeral H5, and it is utilized forlocation of the controlling mechanism, motor, and blowers.

Twin air circulating blowers having the housings I I8 on each side ofthe air conditioning unit are preferably employed. 'These blowers havetheir intake provided by apertures H8 in the baflles H3, 8.. The twinimpellers II1 are of the centrifugal type, and they may be drivendirectly by the motor shaft, or they may be mounted as shown in Fig. 3on the high speed shaft II8, extending from the speed reduction gearingcated at I 28 on each side (Fig. 3), just inside the.

housing II8.

The motor I28 in this embodiment is mounted on the speed reductiongearing, and housing H8, and is provided with the pulley I2I engaged byV-belt I22, which also engages the V-pulley I28 on the shaft H8.

The gear housing II8 contains the usual speed reduction gears connectingthe shaft I I8 with the driving worm screw of the worm conveyor in theconveyor tube I88.

The speed of operation of the feed screw is dean inner walll28 for eachhousing, the wall having an aperture for passing the shaft H8, and bymeans of the spirally extending outer wall I21 for each housing. Theseblowers are adapted to discharge into the space below and surroundingthe furnace housing 58, which also includes all of the space below thehopper 88.

Th upper side walls of the hopper 88 are indiw the filters, exceptthrough the channels between the side panels 25, 28, and baflles H3, H4.

The shaft II8 also supports another impeller I28 of larger diameter andsmaller axial thickness for the purpo e of supplying air at a lesservolume, but of greater pressure, for supporting combustion in the firepot I88. This impeller is housed in a blower housing, one wall of whichis formed by the wall I28 of the left blower (Fig. '1) and the otherwall of which is formed by a plate I88, having an intake aperture I8Isurrounding the shaft 8.

This blower also has a spirally extending outer wall I82, which leads toa discharge opening that communicates with the air tube I 88 leading tothe fire pot I88. The air for this impeller is drawn in from the spaceII5 surrounding the driving mechanism through the intake aperture I8 I rIn the embodiment of Fig. 8 all of the impellers H1, H1, I28 are mountedon the motor shaft I88, which is provided with pulley I2I, belt I22,

driven pulley I23 on the high speed shaft IIO of the gear housing H9.

An axially movable clutch member I34 is splined to the shaft H andengageable with the complementary member on the pulley I23, which ismounted for free rotation on shaft IIO.

In this embodiment the connecting linkage I35 is adapted to disconnectthe drive pulley I23 of the gear housing I I9 entirely from the motorI20 so that there would be either a high rate of feed of coal or no feedat all, while the blowers would continue to operate constantly, beingdirectly connected to the shaft of motor I20.

In the embodiment of Fig. 7, it should also be noted that the speedchanging arrangements I24, I25 affect the speed of the coal feed screwand cannot affect the driven shaft II8, which carries the impellers ofthe air blowers, and which is directly driven by a belt from the motorI20. Thus, the blowers operate at all times when the motor is operating,but the coal feed is adapted to be changed from high to low feed or fromhigh feed to no feed, by reason of the regulation of a controllingsystem further to be described.

The course of the air through the air conditioning unit housing is asfollows: Cold air comes in at the opening 44 (Fig 2) and passes down onboth sides of the bafll 90, which forms the roof of the coal hopper. Itthen passes laterally out through the filters 81, 86 and downwardthrough passages. I36, I31 to the circulating blowers, whose intake islocated at II6. These blowers impel the air rearwardly in the airconditioning unit housing under and around the fur-' nace housing 50,where the air is heated and is passed upwardly into engagement with thelower faces 63 of the heat box at the top of'the furnace until the hotair emerges at the opening 45, where it is conducted into the hot airducts leading to the room: It is returned from the rooms by cold airducts leading to the opening 44 and constantly circulated, while themotor is running, by the circulating blowers. I

A certain amount of the air which is taken in to the space I I5 is usedby the combustion blower I23 and driven through the air tube I09 intothe fire box, where it is'used for supporting combustion of the coal.This air is never wholly shut oil. when the motor is operating, but itsflow may be diminished from high feed to low feed by means of thebutterfly damper II I, which is also controlled by the controlsystem,'further to be described.

This damper closes the air tube I09 partially and greatly reduces theflow of the air for combustion, but provides enough air so that the coalin the fire pot is burned up and the smoke is reduced to a minimum. Infact, so far as I have been able to observe, there is no visible smokeproduced by the operation of the present heating unit All of the partsof the air conditioning unit are preferably made of steel, weldedtogether or otherwise secured by bolts or screws or other suitablefastening means, such as rivets, the welding being preferred, and thesteel is preferably of a type adapted to withstand corrosion, such ascopper bearing steel.

The outside of the unit may be provided with any desired decorativefinish or coating of paint,

and all of the mechanism of the unit, includingv the controllingdevices, may be installed in the Referring now to Fig. 9, this is awiring diagram of a controlling system adapted to be used for operatingthe stoker. The system includes a room thermostat I40, consisting of athermostatic switch located in the rooms to be heated, and having thecontacts I, I42. It also includes a controlling switch assembly, whichconsists of two thermostatic switches, one called the limit switch, I43,and the other called the operating switch, I44. 4 v

The limit switch and the operating switch, in the case of a hot airheater, would be disposed in the plenum chamber, and would consist ofthermostaticelectric switches; but in the case of a steam boiler, thelimit switch and operating switch would consist of pressure actuatedelectric switches, with the pressure responsive device in the boilerexposed to steam pressure. In either case, the limit switch would beprovided with a pair of electric contacts I45, I45, and the operatingswitch with two pairs of electric contacts I41, I40, and I49, I50.

The contacts of the limit switch would be opened only when thetemperature in the plenum chamber reaches or exceeds a predeterminedsafe value, such as, for example, 350 degrees F., or when the steampressure arrives at a predetermined value exceeding safety. At all othertimes the limit switch would have its contacts I45, I46 closed.

The operating switch would be so arranged that an increase oftemperature above 150 degrees F. would open contacts I49, I50 and closecontacts 1, I46; when the temperature of the plenum chamber decreasesbelow 150 degrees F., the contacts 1,. I48 would be opened and thecontacts I49, I50 closed.

This is accomplished by means of the movable switch arm I5I, which ismovable responsive to changes of temperature, by means of a thermostat,or movable responsive to changes in pressure, where the device is usedon a steam boiler.

devices.

main housing so that it is ready to be set in place and merely need beconnected to the electrical circuit and the chimney.

The operating switch may also be disposed in the water of the boiler,and may be movable responsive to the temperature of the water.

The circuit may be energized by means of a volt, 60 cycle lightingcircuit, the leads of which are indicated at I52, I53; and the lead I52may be connected directly to the contact I46.

Contact I45 is connected by a conductor I54 to the movable switch arm,I5I of the o erating switch, and also by a conductor I55 to a terminalA of the transformer I56. This terminal is that of the high voltageprimary I51 of the step-down transformer, the other terminal of which isindicated at B; and terminal B i directly connected to the lineconductor I53.

The fixed contact I40 of the operating switch is connected by conductorI58 to-a terminal D,

and fixed contact I49 is connected by conductor I59 to a terminal C ofthe controlling mechanism.

switch I62 has its contacts I63, 164 connected by conductors I65 and I66to the terminals W and R, respectively. Those circuits connected to theterminals R and W may be controlled either by the pilot switch or theroom thermostat, and may be energized by either of. thes controlling Thepilot switch is an electric switch adapted to be closed periodically, bya pilot clock, indicated at I", which may comprise an electric motorclock. This clock is energized by conductor I68 from terminal B, whichis connected to line at I53, and by conductor I69, which leads toterminal C that is connected by conductor I59 to the operating switchcontact I49 for a purpose further to be described.

The terminal W is connected by conductor I10 to one terminal of a relaycoil I1I, the relay controlling the contacts I12 and I13. The otherterminal of the relay coil is connected by conductor I14 to thesecondary I15 of the step-down transformer, which has its other terminalconnected by conductor I16 to the terminal R. Thus the room thermostatis connected in series with the secondary of the transformer and withthe relay coil I1I so that when the room thermostat contacts I4I, I42are closed the relay IN is energized to close the contacts I12, I13.

The same result may be accomplished by means of the closing of the pilotswitch contacts I68, I64. The relay contacts I12, I13 control theenergization of the motor I20, which drives the blowers for circulatingair, and for the air of combustion, and which also drives the feed screwof the stoker.

The motor I has its terminals connected by conductors I11 and I18 toterminals E and F. Terminal E leads back through conductor I19 toterminal A, and through conductor I55 to contact I45. This is ordinarilyconnected to contact I46, which is connected to conductor I52 of theline. The other lead from the motor I20, vwhich is indicated at I18, isconnected through the terminal F and a conductor I80 to relay contactI12. Relay contact I13 is connected by conductor I8I to the terminal B,which is directly connected to the line at I53. Thus the motor isadapted to be controlled by the relay HI and energized by it wheneverthe limit switch is closed; but the limit switch is adapted todeenergize the whole system through its direct breaking of theenergizing circuit at the contacts The controlling circuit also includesa pair of solenoids, one of which may be termed the off and minimum airsolenoid, and the'other the "high solenoid. -Each of these solenoidsincludes a coil, indicated at I82, for the ofi and minimum air solenoid;and I83 for the high" solenoid. The high" solenoid has its coilconnected by conductor I84 to the terminal C. This terminal is connectedby conductor I59 to contact I49. The contacts I49, I50 may be called thehot contacts of the operating switch because they are opened when theoperating switch reaches the hottest operating temperature forthe plenumchamber.

The contacts I41, I48 may be called the cold contacts because they areclosed when the plenum chamber is hot enough, and the next cycle permitsthe cooling of the plenum chamber untilit reaches a predetermined lowertemperature.

The other terminal of the solenoid coil I83 is connected to a contactI85, which is adapted to be engaged by the contact I86 of a movableswitch arm I81. This movable switch arm has another contact I88 at itsopposite end, adapted to engage the contact I89, which is connected toone terminal of the oil and minimum air solenoid I82. The other terminalof this solenoid is con nected by conductor I90 to the terminal D, whichleads back through conductor I58 to contact I4l8.

The switch arm I81 is connected by conductor I9I to the terminal F ofthe motor circuit. Thus both of these solenoids are adapted to be con-I95, which engages the switch arm trolled by the relay in, through itscontacts I12, I13, and, also by the operating switch I44 through itscontacts I48 and I49.

The operation of the foregoing system is as follows: When thetemperature of the plenum chamber does not exceed a safe temperatureofsay, for example, 350 degrees F., the limit switch contacts I45, I46will be closed, and the stepdown transformer I56 will have its primaryenergized through the following circuit: line conductor I53, primaryI51, conductor I55, contacts I45, I46,conductor I52.

Suppose, for example, under these conditions the temperature of theroom, in which the room thermostat is located, decreased below thethermostat setting. The room thermostat contacts I4I, I42 would close,and this would close the circuit through the secondary I15 of thetransformer I56, as follows: contacts I4I, I42, conductor I6I, relayl1l, conductor I14, secondary I15, conductor I16, conductor I60, tocontact MI.

The closure of the secondary circuit energizes the relay coil I1I,closing the relay contacts I12, I13. This completes the motor circuitthrough the following conductors: contact I12, conductor I80, conductorI18, motor I20, conductor I11, conductor I19, conductor I55, contactsI45, I46, conductor I52, to the line conductor I53, conductor I8I,contact I13.

The motor then drives the air circulating blowers and the air combustionblower and the gears which actuate the feed screw for the stoker. Thefuel bed is supplied with additional coal and a blast of air forcombustion.

If at this time the temperature of the heating plant, that is, theplenum chamber, is below degrees F., or if the steam pressure is below apredetermined value, the contacts I49, I50 are closed.

Assuming the contacts I85, I86 of the high solenoid are closed, thiswould energize the high solenoid I83 through the following circuit:contacts I85, I86, switch arm I81, conductor I9I, conductor I80,contacts I12, I13, conductor I8I, conductor I53, to line conductor I53,contacts I45, I46, conductor I54, switch arm I5I, conductors I49, I50,conductor I59, conductor I84, solenoid I83, contact I85.

The energization of the high solenoid I83 will cause its core to bedrawn into the solenoid, and the core has an insulating extension I81and opens the contacts I85, I86, closing the contacts I88, I89. The highsolenoid plunger I83 is adapted to actuate the member I24 on the gearcase H9 and put the coal feed on high. It also actuates the-Stoker airshutter III to the high or open position; but it leaves these devicesunder the control of the solenoid I82 because of the closure of thecontacts I88, I89.

The solenoid I 83 is removed from its controlling posltion by theopening of contacts I85, I86. The stoker will then be fired on high,that is, with the maximum feed of coal and air, and the firing at thisrate will continue until change of temperature conditions is broughtabout in the room or in the plenum chamber acting on the operatingswitch.

Suppose, for example, the thermostat called for heat and the heatingplant, that is, the pletum chamber, has its temperature already above150 degrees F. The contacts I49, I50 would then be opened, and thecontacts I41, I48 would circuits by virtue of the closure of thecontacts I12, I13 of the relay to energize the i! and minimum airsolenoid I82 through its contacts I88, I89.

It should be understood that the question whether the air or coal feedis merely reduced or-turned completely off depends uponthe adjustment ofthe stops on the gear box H8.

The core of this solenoid would be pulled up, changing the coal feedfrom high to off, and cutting the air supply to a minimum by closing theshutter III, although the blower for combustion air would still beoperating whenever the motor I28 is energized.

At the end of its inward stroke, the plunger of solenoid I82 would breakthe contacts I88, I88 andclose the contacts I85, I88 by means of aninsulating plunger extension I98. Under these conditions, with thetemperature of the plenum chamber already above. 150 degrees F., thefire bed would be supplied with a minimum amount of air for combustionand fed with coal at a low rate offeed.

The air condition circulating blower would deliver warm air to the spaceto be heated, until the room thermostat is satisfied, unless the firegets too low to maintain the 150 degrees F. temperature. If the fire bedshould get that low, then the contacts I41, I48 would open, andconvtacts I49, I 58 would close, cutting the stoker on high coal feedand high air feed.

Under all of these conditions, the limit switch would still be in fullcontrol of the system, and it would not allow the stoker to operate atall if the heating plant temperature were higher than a safe temperaturesetting, such as, for example, 350 degrees F.

The contacts I83 and IE4 of the pilot coil switch are for pilot orkindling operations to maintain a small fire between the periods of theoperation of the stoker responsive to thermostat heat demands.

Whenthe limit switch contacts are open, it should be noted that even thepilot switch is not energized, and the pilot cannot start the stokerunder these conditions. This is of great advantage because it tends tokeep down the temperature over-run of the furnace.

It should also be noted that if the limit switch contacts are closed thepilot switch may operate; but. if the contacts I49, I50 are open,thepilot operation will be with the coal feed off and the air at aminimum. This-will eliminate temperature over-run of the-furnace. Inother words,

the operation of the pilot switch for kindling padapted to be used notonly for the present air conditioning and heating unit, but for stokerswhich are installed in old furnaces. In such case the coal feed wouldnot be completely cut oil, but would be merely reduced from high to low,such as from a No. 4 feed on high, to a No. 1 feed on low, asexemplified by the mechanism of Fig. "I. In the installations having thepresent air conditioning and heating unit, the coal feed is preferablycompletely out off, when the air feed is cut to a minimum, asexemplified by the use of a clutch in Fig. 8.

It will thus be observed that I have invented an improved airconditioning and heating unit,

in which a single motor is adapted to. drive the air circulating blowersand the blowerfor combustion air. i

This unit contains all of thestructure necessary for the circulation ofthe air, filtering and heating and its controlling apparatus, and, maybe shipped from the factory and installed as a unit. Its hopper isenclosed in the housing. The arrangement is such that all of theelements necessary for the operation of the stoker and circulation ofthe air are enclosed in one unitary housing.

The efiiciency of the present air conditioning and heating unit ishigher than that attained by any of the devices of the prior art for thereason that more perfect combustion is secured and the coal bed is keptat a minimum depth. Temperature over-run of the furnace is elim inatedor minimized by cutting the feed of the coal from high to zero orlow'and reducing the air blast from high to low after a predeterminedperiod of operation on high coal feed.

I have found that installations embodying the present system willmaintain the room tempera ture of a stoker fired system so uniform thatit does not vary one-half degree F. during a twenty-four hour period ofoperation, while the outside temperature drops from 44 degrees F. to 12degrees F. below zero. The same room thermostatwhich, with the devicesof the prior art, could not hold the room or laboratory-within fivedegrees F. of the setting of the room thermostat, was adapted, with thepresent system, to maintain the temperature substantially constant, withno variation of more than one-half degree F.

Temperature over-runs were eliminated because the green coal forced inon high firing is substantially all burned up just before the thermostatis satisfied on the low firing.

I desire it to be understood that the temperatures which are used asexamples in this description are not limitative in any sense, and thepresent devices may be arranged to operate at any temperatures suitablefor stoker fired heating plants.

The present air conditioning unit may also be used with a bin feedstoker, in which case the coal will be fed to the burner from a bininstead of from the hopper, as shown, involving the use of a longerscrew and screw housing, but the other structure of the unit may besubstantially the same.

WhileI have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but

desire to avail myself of all changes within the scope of the appendedclaims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1 1. In an air conditioning and heating system,

the combination of a furnace unit housing prohaving an air pipeextending to said furnace, speed reduction drive means driven by saidmotor, coal feeding means driven by said drive means for supplying fuelto said furnace, thermostatic controlling means controlled by thetemperature of the air in the plenum chamber for controlling said fuelfeeding means, and an air damper in said air pipe from said combustionair blower for diminishing the flow of combustion air when the rate ofcoal feed is cut down, the circulating blowers and combustion air bloweroperating at all times when the electric motor is driven.

2. In an air conditioning and heating system, the combination of afurnace unit housing provided with a furnace at one end and providedwith an inlet at its opposite end, blower means for receiving the airfrom said inlet and directing it toward said furnace, said housing beingprovided with a hot air outlet, an electric motor for driving saidblower means, combustion air blower means driven by the same electricmotor and having an air pipe extending to said furnace, speed reductiondrive means driven by said motor, coal feeding means driven by saiddrive means for supplying fuel to said furnace, thermostatic controllingmeans controlled by the temperature of the air in the plenum chamber forcontrolling said fuel feeding means, and an air damper in said air pipefrom said combustion air blower for diminishing the flow of combustionair when the rate of coal feed is cut down, the circulating blowers andcombustion air blower operating at all times when the electric motor isdriven, said thermostatic means comprising an operating switch in theplenum chamber, having alternate pairs of contacts to be broken orengage alternately, depending upon the temperature, whereby the coalfeed is cut to a low rate as soon as the temperature in the plenumchamber reaches a predetermined value.

3. In an air conditioning and heating system, the combination of afurnace unit housing provided with a furnace at one end and providedwith an inlet at its opposite end, blower means for receiving the airfrom said inlet and directing it toward said furnace, said housing beingprovided with a hot air outlet, an electric motor for driving saidblower means, combustion air blower means driven by the same electricmotor and having an air pipe extending to said furnace, speed reductiondrive means driven by said motor, coal feeding means driven by saiddrive means for supplying fuel to said furnace, thermostatic controllingmeans controlled by the temperature of the air in the plenum chamberfor'controlling said fuel feeding means, and an air damper in said airpipe from said combustion air blower for diminishing the flow ofcombustion air when the rate of coal feed is cut down, the circulatingblowers and combustion air blower operating at all times when theelectric motor is driven, said thermostatic means comprising anoperating switch in the plenum chamber, having alternate pairs ofcontacts to be broken or engage alternately, depending upon thetemperature, whereby the coal feed is cut to a low rate as soon as thetemperature in the plenum chamber reaches a predetermined value,

and a room thermostat for controlling the energization of said motor,said room thermostat operating said motor until the demand for heat.

nace, an electric driving motor, combustion air blower means driven bysaid electric motor and having an air pipe extending to said furnace,speed reduction drive means'driven by said motor and actuating said coalfeeding means, said speed reduction drive means being variable for highor low feed of coal, means for controlling the flow of combustion air insaid air pipe, and

controlling means controlled by the condition of the. furnace in respectto heat generation for transmission to the space to be heated forcontrolling the positionsof said speed reduction drive means and saidmeansfor controlling flow of combustion air.

5. A control system for stokers comprising a double-throw thermostaticelectric switch having high temperature and low temperature contacts,coal feeding means and combustion air feeding means, an electric motorfor driving said coal feeding and air feeding means, operativemechanical connections between said motor and said coal feeding means,and said air feeding means, and electrical means controlled by saiddouble-throw thermostatic switch responsive to the temperature conditionof air in the plenum chamber of the furnace for controlling the rate ofsupply of air and coal by said feeding means, whereby the fire issupplied with air and coal as required to maintain the furnace withinpredetermined temperature limits.

6. A control system for stokers comprising a double-throw thermostaticelectric switch having high temperature and low temperature contacts,coal feeding means and combustion air feeding means, an electric motorfor driving said coal feeding and air feeding means, operativemechanical connections between said motor and said coal feeding meansand said air feeding means, and electrical means controlled by saiddouble-throw thermostatic switch responsive to the temperature conditionof air inthe plenum chamber of the furnace for controlling the rate ofsupply of air and coal by said feeding means, whereby the fire issupplied with air and coal as required to maintain the furnace withinpredetermined temperature limits, said air feeding means being operatedcontinuously for the purpose of removing smoke at all times and burningup the excess coal forced into the fire pot during operation of the coalfeeding means.

7. A control system for stokers comprising a double-throw thermostaticelectric switch having high temperature and low temperature contacts,coal feeding means and combustion air feeding means, an electric motorfor driving said coal feeding and air feeding means, operativemechanical connections between said motor and said coal feeding meansand said air feeding means, electrical means controlled by saiddouble-throw thermostatic switch responsive to the temperature conditionof air in the plenum chamber of the furnace for controlling the rate ofsupply of air and coal by said feeding means, whereby the fire issupplied with air and coal as required to maintain the furnace withinpredetermined temperature limits, a circulation air blower driven by thesame electric motor, and a room thermostatic switch for controlling theoperation of said motor separately from said double-throw thermostaticswitch and adapted to energize the motor when there is a demand for heatin the room,

8. A control system for stokers comprising a double-throw thermostaticelectric switch having high temperature and low temperature contacts,coal feeding means, and combustion air feeding means, an electricalmotor for driving said coal feeding and air feeding means, opera- ;tivemechanical connections'between said motor and said coal feeding meansand said air feeding means, electrical means controlled by said dou- 4ble-throw thermostatic switch responsive to the temperature condition ofair in the plenum chamber of the furnace for controlling the rate ofsupply of airand coal by the said feeding means, whereby the fire issupplied with air and coal as required to maintain the furnace "withinpredetermined temperature limits, a circula- 1 to energize the motorwhenthere is a-demand for heat in the room, and a safety limit switchcomprising .a thermostatic switch adapted to be opened at apredetermined high limiting temperature of the furnace, controlling theenergization of all the circuits of said system.

' 9. A- control system for stokers comprising a double-throwthermostatic electric switch hav-v ing high temperature and lowtemperature contacts, coal feeding means and combustion air feedingmeans, an electridmotor for driving said coal feeding and air feedingmeans, operative mechanical connections between said motor and said coalfeeding means and said air feeding means, electrical means controlled bysaid double-throw thermostatic switch'responsive to the temperaturecondition of air in the plenum chamber of the furnace for controllingthe rate of supply of air and coal by said feeding means, whereby thefire is supplied with air and coal as required to maintain the furnacewithin predetermined temperature limits, and a periodically actuatedtime controlled pilOt switch separately controlling the energization ofsaid motor for turning. on the motor and feeding coal and air tothe'furnace periodically to maintain the fire, 10. A control system forstokers comprising a double-throw thermostatic-electric. switch havinghigh temperature-and low temperature contacts, coal feeding means andcombustion air feeding means, an electric motor for driving said coalfeeding and air feeding means, operative mechanical. connections betweensaid motor and said coal feedingmeans and said air feeding means,electrical means controlled by said douhie-throw thermostatic switchresponsive to the temperature condition of air in the plenum chamber ofthe furnace for controlling the rate of supply ofair and coal by saidfeeding means, whereby the fire is supplied with air and coal asrequired to'maintain the furnacewithin predetermined temperature limits,and a periodically actuated time controlled pilot switch separatelycontrolling the energization of said motor for turning on the motor andfeeding coal and air to the furnace periodically to maintain the tire,said system being arranged to feed the fire pursuant to energization bythe pilot switchon high or low feed, depending on the temperature of airin the plenum chamber responsive to said double-throw thermostaticwitch.

11. A stoker controlled system comprising a heaterhaving a fire pot,coal feeding means for feeding coal to said fire pot, a combustion airblower for supplying air to said heater, an electric motor for drivingsaid .blower and coal feeding means, a selective drive interposedbetween said coal feeding means and said motor, having two rates ofdrive, one for low coal feed, and one for high coal feed, electriccontrol means for said motor located at the heater and adapted to beactuated responsive to the condition of the heater in respect to thegeneration of a predetermined supply of heat at the heater, coal feedcontrol means arranged and constructed to move said selective drive tohigh or low coal feed, depending upon said controlling means, saidcontrolling means effecting a low coal feed when the heater reaches apredetermined high temperature, and a high coal feed when said heaterreaches'a predetermined low temperature, con

trolling means located in a room to be heated, generated at said heater,for controlling the supply of heat to said room responsive to the demandfor heat in the room, a time controlled,

switch means for controlling the energization of said motor andeffecting a coal feed at predetermined periods of time to act as a pilotand maintain combustion, and limit switch means controlling all of theelectric circuits of said system and adapted to de-energize the systemupon the reaching of a predetermined higher temperature at said heater.

12. A stoker'controlled system comprising a fire pot, a coal feedingmeans for feeding coal to said fire pot, selective drive means foractuating; said coal feeding means at one of two rates of feed,comprising high coal feed and low coal feed, an electric motor,operative connections between said electric motor and said selectivedrive, a combustion air blower driven by said motor, an air circulationblower driven by said motor, a motor controlled relay for controllingthe energization of said motor, a high ,voltage electric circuit forenergization of said motor, a transformer energized from said highvoltage circuit and adapted to provide low voltage for energizing saidrelay, an operating switch for controlling the energization of saidrelay and through it of, the motor, said opjerating switch comprising athermostatically actuated switch located in the plenum chamber of afurnace housing surrounding said fire pot, electrically controlled meansfor controlling the selection of high or low coal feed by said selectivedrive, said electrically controlled means being controlled by saidoperating switch to provide a low coal feed when the temperature oftheplenum chamber reaches a predetermined high value and high coal feedwhen the temperature of the plenum chamber reaches a predetermined lowvalue. I

13. A stoker controlled system comprising a fire pot, a coal feedingmeans for feeding coal to said fire pot, selective drive means foractuating said coal feeding means at one of two rates of feed,comprising high coal feed and low coal feed, anelectric motor, operativeconnections between said electric motor and said selective drive, acombustion air blower driven by said motor, an air circulation blowerdriven by said motor, a motor controlled relay for controlling theenergization of said motor, a high voltage electric circuit forenergization of said motor, a transformer energized from said highvoltage circuit and adapted to provide low voltage for energizing saidrelay, an operating switch for controlling the energization of saidrelay and through it of the motor. said operating switch comprising athermostatically actuated switch located in the plenum chamber of afurnace housing surrounding said fire pot, electrically controlled meansfor controlling the selection of high or low coal feed by said selectivedrive, said electrically controlled means being controlled by saidoperating switch to provide a low coal feed when the temperature of theplenum chamber reaches a predetermined high value and high coal feedwhen the temperature of the plenum chamber reaches a predetermined lowvalue, and a thermostatic limit switch for controlling the energizationof all of the circuits of said system whereby the system istie-energized when the temperature in the plenum chamber reaches apredetermined upper value.

14. A stoker controlled system comprising a fire pot, a coal feedingmeans for feeding coal to said fire pot, selective drive means foractuating said coal feeding means at one of two rates of feed,comprising high coal feed and low coal feed, an electric motor,operative connections between said electric motor and said selectivedrive, a combustion air blower driven by said trolled means forcontrolling the selection of high or low coal feed by said selectivedrive, said electrically controlled means being contnolled by saidoperating switch to provide a low coal feed when the temperature of theplenum chamber reaches a predetermined high value and high coal feedwhen the temperature of the plenum chamber reaches a predetermined lowvalue, and air valve means for controlling the inlet of air to saidcombustion blower, said air valve means being partially closed when thecoal feed is on low feed and open to a predetermined amount when thecoal feed is on high feed, by means of an operative mechanicalconnection between said valve and said controlling means.

15. A stoker controlled system comprising a fire pot, a coal feedingmeans for feeding coal to said fire pot, selective drive means foractuating said coal feeding means at one of two rates of feed,comprising high coal feed and low coal feed, an electric motor,operative connections between said electric motor and said selectivedrive, a combustion air blower driven by said motor, an air circulationblower driven by said motor, a motor controlled relay forcontrolling theenergization of said motor, a high voltage electric circuit forenergization of said motor, a transformer energized from said highvoltage circuit ing said fire pot, electrically controlled means forcontrolling the selection of high or low coal feed by said selectivedrive, said electrically controlled means being controlled by saidoperating switch to provide a low coal feed when the tem-. perature ofthe plenum chamber reaches a predetermined high value and high coal feedwhen the temperature of the plenum chamber reaches a predetermined lowvalue, and air valve means for controlling the inlet of air to saidcombustion blower, said air valve means being partially closed when thecoal feed is on low feed and opened to a predetermined amount when thecoal feed is on high feed, by means of an operative mechanicalconnection betweensaid valve and said controlling means, and means formaintaining combustion at a rate dependent upon the position of theoperating switch for energizing said relay at predetermined timeintervals to drive the motor and maintain combustion.

- 16. A stoker controlled system comprising a -fire pot, a coal feedingmeans for feeding coal to said fire pot, selective drive means foractuating said coal feeding means atone of two rates of feed, comprisinghigh coal feed and low coal feed, an electric motor, operativeconnections between said electric motor and said selective drive, acombustion air blower driven by said motor, an air circulation blowerdriven by said motor, a motor controlled relay for controlling theenergizati'on of said motor, a high voltage electric circuit forenergization of said motor, a transformer energized from said highvoltage circuit and adapted to provide low voltage for energizing saidrelay, an operating switch for controlling the energization of saidrelay and through it of the motor, said operating switch comprising athermostatically actuated switch located in the plenum chamber of afurnace housing surrounding said fire pot, electrically controlled meansfor controlling the selection of high or low coal feed by said selectivedrive, said electrically controlled means being controlled by saidoperating switch to provide a low coal feed when the temperature of theplenum chamber reaches a predetermined high value and high coal feedwhen the temperature of the'plenum chamber reaches a predetermined lowvalue, and a room thermostat connected to control said relay and adaptedto effect an energization of said motor, and a feed of coal when thereis a demand for heat in the room, the rate .of coal feed being dependentupon the temperature in the plenum chamber and being controlled by saidoperating switch.

WIILIAM W. HALIJNAN.

